Screw propeller



Dec. 28 1926. 1 1,612,110

A. K. FUNGER SCREW PHJ/PELLE?! Filed Nov. 25I 19:34 1 2 Sheets-Sheet 1 FigA.

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S CREW PROPELLER Filed Nov. 25, 1924 2 Sheets-Sheet 2 Patented Dec. 28, `1.926.4

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application mea November 25, im, sensing, 'assaggi-ena ia cermay January. Le, use.

All heretofore known screw? propellers'for wind turbines or` the like consist of a. con? tinuous screw surface whose pitch is at first steep and then diminishing towards the .outer end o'f the propeller win It has been found tofbe impossible to so s ape sald pro'- peller'wing, as to Aafford the highest degree.

of eiiic'ienoy first inrespect `to the driving "-'power and secondly in respect to the mechanicali eiect. Apart from this, in almost all cases, there remains a 'zene'on the propeller 4wing inwhich the Wind power 1s 'not fully eiectwe. It 'is well known that to 'produce a powerful drive, it is necessary that at l5 the inner part ofthe propeller wing, i. e., the one directed towards the center, the pitch be high (starting say with 45), while the outer part ion .which the'wind power Iacts must have a proportionately much smaller pitch.

..20 These two` conditions cannot be attained in' a continuons' propeller surface., In. rac'tice always one condition -will hav`e .to e sub-` ordinated to the 'other condition.

The "invention has. for its object' solve-, '95. ,this problem` by dividin the propeller wing vlongitudinally'preferab y into two sections. The inner'se'ction', i. e., the section d1rected Atowards,the center of the turbine wheel can then, irrespective 01|?l therequirements as'to f the outwardly directed section, be 'given ai Ahigh pitch and the outer section se'rymg forthe errer-.transmission may be' given the-desire lowlliverfpit'ell.` ,Whenpgthe two sectionscan be Asep''aratel'y"tixedjo'. the known ring;

supports of the turbine wheel, it is'advan-` tgeous to ,join them at their junction by an angle piece shapedso `that the .two sections of the propeller, when fixed to, the angle piece are properly.;positioned.- `To vthis end, the

` g. angle (piece is,formed`rvith flanges, which are curve not only to conformwith the pitch ofthe adjoining sections, but arealso so displaced relative to one` another that the two sections of the propeller intersect one another.` .l

The angle piece may also be provided with a guide :for the ring body joining the individual propeller winds, `in order that when .f

assembled the latter'becomes kproperly posiel .50 tioned. A 'f It is urther advantageous that the ,edge

of the propeller wing, which yrelative to the direction of rotation is directed rearwardly, be bent upwardly inthe outward direction, i. e., rearwardly relative tothe direction vof relative positions are seen in Fig. 5, I

of.. this edge onthe side of the propeller wing directed opposite the wind, that enables this? the wind..l This a'ords space for the .joinin the ro'peller-y wings and -at the samef time avora lejcurrent conditions, sinoean-.l under pressure is .produced in the vicnityi corresponding parts yand in which Fig. 1 is a perspectlve view of the air turbine wheel; F1g. 2 afront elevation ot my new ro ellerjA wing according to its geometric s a Fig. 3 'a front. elevation. of the spira ly shaped propeller wing; Fig.- 4a view `of the outer endof thepropeller win Fig-J5 a cross sectlon at the junction of t e wing sections; Fig.y 6 an elevation ofan angle piece serving as a joint for the two wing` sections; Fi'g. 6* a plan view thereof; Fig. 6". a verti- Fig. 6 asimilar cross section on line (if-6 of Fig. 6*; Fig. 7 shows diagrammatically 'cal cross section on line 6"--6b of Fig. 6*;

the arrangement ofthe two wing sections displaced relative to. or separated from one another. i

In `the vexample shown, the pro eller wing is .composed of. two 'sections a and b.

The section b, which relative to the center of the wheel constitutes lthe inner section,.is

curved in form of a screw with a high itch', l which, for example,.at 8 may be 45 an at y `may -bef 30. Thesecond section a,v which 'relativeto-the centerof the wheel is directed outwardly, begins .with a smaller pitch, say

22, at and ends with an angle of 10 at a.' V l bI n this manner, the highly curved inner secjtionb is part1cularly adapte-d to produce a powerful ldrive, whilethe section e acts as an excellent. means for transmitting the power. The transmission zone being elimi'A nated; there isnowhere on thawing surfaces a part of inferior efficiency. v A

For joining the two wing sections, whose employl anangle piece shown in Figs. 6, 6, 6b and 6.` This angle piece consistsofa body portion c formed withv langes'd, e. Section a'olf' the .1 Wing is riveted oi" otherwisexed to the'flange d and the section b to flange e,

as indicated by dotted lines in Fig. 6.' The- A flanges d and e are' curved at their junction in conformity withthe curvature-of the corresponding wing sections, so that the wing sections bear evenly thereon. The flanges arealso displaced or arranged to intersect one another, as a result of which the adjoinin ends of the wing sections are located on erly positioned in the wheel, the body por- `tion c is provided with a U-shaped extension f. The latter is formed with two longitudi-v nal end flanges g, which form between themselves a groove. In this groove constituting a socket is adapted to lit the. well-known ring member, that serves to join all propeller `wings to the turbine wheel, and which is adapted to pass through 'a slit L of the angle 1ece. p As seen from Fig. 4, the wing section a in the vicinity of the edge z', which, relative to the direction of rotation, is directed rearwardly, is bent outwardly relative to the direction of the air current indicated by the arrows in Fig. 4. By this bend, not only is space provided for the accommodation of the usual fastening ring, which is arranged in well-known manner near the outer end of the wing section a, but additionally an under pressure or even suction is produced behind said edge z', so that the bet edge, during the rotation of the wheel, always passes through an almost completely evacuated space and thus-doesl not meet with-any appreciable resistance.

What I claim is c 1. Ina wind turbine, a screw4 propeller wing composed longitudinally'of a plurality of separate screw curved sections havingdifferent outwardly diminishing pitch.

' 2. In a wind turbine, a screw propeller* with the pitch of said sections and intersecting one another.l

4. In a wind turbine, a lscrew propeller wing composed longitudinally of a plurality of screw `curved sections of different out- I wardly diminishing pitch,`the outwardly directed section having its edge, which relative to the direction of rotation is located at the rear of the propeller wing, bent outwardly or rearwardly relative to the air current.

5. In a windturbine` propeller wings, each composed longitudinally of a plurality of sections, an angle piece for joining the sections of each propeller wing together, each angle piece being formed wlth a socket and an annular member assing through said sockets for holding sald propeller wings together in proper position on the turbine wheel. Y Y

6. In a wind turbine, a vpropeller wing divided longitudinally into a plurality of sections, each of which is twisted into the shape of a screw of diferent pitch, so as to form an interrupted screw line, the end of `each wing section directed toward the center being at a higher pitch relative to the direction of motion than that of the end directed toward the periphery.

-In testimonywhereof I aiiix myA signature.

ALFRED KURT FUNGER.' 

